Abstract An effective cellulose-based antiscalant, namely, carboxymethyl cellulose-graft-poly(acrylic acid) (CMC-g-PAA) was synthesized via the graft copolymerization of carboxymethyl cellulose (CMC) and acrylic acid. The addition of CMC-g-PAAs can evidently delay the formation of the CaSO4 scale, effectively mitigate reverse osmosis (RO) membrane scaling and flux decline, and increase the induction time of crystallization due to the grafted carboxyl groups efficiently interacting with scale-forming substances. The inhibition performance of CMC-g-PAA in the static test was mostly consistent with that in the RO test. Combining the results of the RO and static tests and the relevant characterizations by scanning electron microscopy, optical microscope, x-ray diffraction, and conductivity measurements, the scale-inhibition mechanisms of CMC-g-PAA are mainly ascribed to enhanced chelation, dispersion, and threshold effects. Moreover, the two structural factors of CMC-g-PAAs, grafting ratio and grafted-chain distribution, play important roles in their inhibition effects. Appropriate grafting ratio was necessary to obtain high-performance CMC-g-PAA. With a similar grafting ratio, a higher average number of PAA grafted chains can lead to better inhibition performance because of more active inhibition sites contained. However, the grafting ratio has more contributions than grafted-chain distribution. This study provides a better understanding of the structure–activity relationship of the grafting-modified polymeric inhibitor and fundamental guidance for the exploitation and design of novel and efficient scale inhibitors.

中文翻译：

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结构对各种接枝纤维素基阻垢剂在 RO 膜结垢控制中阻垢性能的影响评价

摘要 通过羧甲基纤维素（CMC）与丙烯酸的接枝共聚，合成了一种有效的纤维素类阻垢剂，即羧甲基纤维素接枝聚丙烯酸（CMC-g-PAA）。CMC-g-PAA的加入可以明显延缓CaSO4水垢的形成，有效缓解反渗透（RO）膜结垢和通量下降，由于接枝的羧基与水垢形成有效相互作用，增加了结晶诱导时间物质。CMC-g-PAA在静态试验中的抑制性能与RO试验中基本一致。结合 RO 和静态测试的结果以及扫描电子显微镜、光学显微镜、X 射线衍射和电导率测量的相关表征，CMC-g-PAA 的阻垢机制主要归因于增强的螯合、分散和阈值效应。此外，CMC-g-PAA的两个结构因素，接枝率和接枝链分布，在其抑制作用中起重要作用。适当的接枝率是获得高性能 CMC-g-PAA 所必需的。在接枝率相似的情况下，由于含有更多的活性抑制位点，更高的平均 PAA 接枝链数可以导致更好的抑制性能。然而，接枝率比接枝链分布有更多的贡献。该研究为更好地理解接枝改性聚合物阻垢剂的构效关系提供了更好的理解，并为开发和设计新型高效阻垢剂提供了基本指导。